Air filter



FIG. 1 is a first perspective view of the filter embodying our new design;

FIG. 2 is a second perspective view the filter of FIG. 1;

FIG. 3 is a top view the filter of FIG. 1;

FIG. 4 is a first side view the filter of FIG. 1;

FIG. 5 is a second side view the filter of FIG. 1;

FIG. 6 is a third side view the filter of FIG. 1; and,

FIG. 7 is a fourth side view the filter of FIG. 1.

Although not shown, a bottom view of the filter of FIG. 1 is identical to the top view shown in FIG. 3 and corresponds to an opposite side of the filter shown in FIG. 3.

In the drawings, the broken lines show portions of the filter that form no part of the claim. 

CLAIM The ornamental design for an air filter, as shown and described. 